Which statement best defines the solution of a system of two linear equations in two variables?

Rearrange and solve for $x$:

$-2(3x+4)+5=x-7$

Solve the system using substitution: { y = (3/4)x - 2 ; (1/2)x + (3/2)y = 6 }

Consider the system $\{\begin{array}{c}y=3x-5\\ 2x+y=7\end{array}$. Perform the substitution and determine the value of $x$.

A store sells pens and notebooks. Pens cost \$2 each and notebooks \$3 each. A customer buys some combination totaling \$29 for 11 items. Let p = pens, n = notebooks. If p = 11 - n, substitute and find the number of notebooks bought.